Apparatus and method for harvesting energy in an electronic device

ABSTRACT

An apparatus, a method, and a computer program product are provided. The apparatus may be an electronic component. The electronic component includes at least one energy harvester coupled between at least one pair of hot and cold regions of the electronic component and configured to convert thermal energy to electrical energy in order to provide power to at least the electronic component, the at least one energy harvester including a radiative thermal channel or a conductive thermal channel. A first end of the conductive thermal channel is coupled to a first semiconductor material and a second end of the conductive thermal channel is coupled to a second semiconductor material, the first semiconductor material being coupled to the hot region and isolated from the cold region and the second semiconductor material being coupled to the cold region and isolated from the hot region.

BACKGROUND

1. Field

The present disclosure relates generally to harvesting energy, and moreparticularly, to an apparatus and method for harvesting energy in anelectronic device.

2. Background

Mobile electronic devices generally use a battery, which can typicallysupply power for only a few hours at a time based on the capacity of thebattery and the usage of the mobile electronic device. Accordingly,there has been a substantial effort toward the development of techniquesfor reducing power consumption of the electronic components in themobile electronic devices. However, as the demand for performance fromthe electronic components in such mobile electronic devices continues toincrease, a substantial amount of thermal energy, i.e., heat, isgenerated by the electronic components despite the techniques forreducing power consumption.

For example, there is an increasing demand for advanced features andperformance in specific areas, such as modems, multimedia, and highspeed serial interfaces. To support such advanced features, mobile,applications, media, and modem processor integrated circuits (ICs) arenow being designed to include multiple central processing unit (CPU)cores. For example, the power consumption of a Krait CPU core isestimated at 1 watt (W). For quad Krait CPU cores, the estimated powerconsumption will increase linearly to 4 W if used concurrently. Asubstantial amount of resources have been allocated to reduce orminimize thermal impacts that may result from the increase of devicetemperatures as operating power consumption increases.

However, if such thermal energy generated by an electronic component maybe converted to electrical energy, the mobile electronic devices will beable to support more advanced features and longer standby times. Inaddition, engineering efforts for reducing power consumption of theelectronic components in the mobile electronic devices may be directedtoward other areas in need of development.

SUMMARY

In an aspect of the disclosure, an apparatus, a method, and a computerprogram product are provided. The apparatus may be a mobile electronicdevice, such as a mobile phone. The mobile electronic device includes anelectronic component and at least one energy harvester coupled betweenat least one pair of hot and cold regions of the electronic componentand configured to convert thermal energy to electrical energy in orderto provide power to at least the electronic component, the at least oneenergy harvester including a radiative thermal channel or a conductivethermal channel. A first end of the conductive thermal channel iscoupled to a first semiconductor material and a second end of theconductive thermal channel is coupled to a second semiconductormaterial, the first semiconductor material being coupled to the hotregion and isolated from the cold region and the second semiconductormaterial being coupled to the cold region and isolated from the hotregion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an energy harvester configuration forconverting thermal energy to electrical energy via a conductive thermalchannel.

FIG. 2 is a diagram illustrating an exemplary electrical circuit showingthe energy harvester driving an electrical load.

FIG. 3 is a diagram illustrating a semiconductor die configured with anenergy harvester.

FIG. 4 is a diagram illustrating a semiconductor die configured with anenergy harvester.

FIG. 5 is a diagram illustrating a top view of a multiple semiconductordie configuration including an energy harvester.

FIG. 6 is a diagram illustrating a top view of a multiple semiconductordie configuration including an energy harvester.

FIG. 7 is a diagram illustrating an energy harvester configuration forconverting thermal energy to electrical energy via a radiative thermalchannel.

FIG. 8 is a diagram illustrating a top view of a multiple semiconductordie configuration including an energy harvester.

FIG. 9 is a diagram illustrating a cross sectional view of the multiplesemiconductor die configuration shown in FIG. 8.

FIG. 10 is a block diagram illustrating an electronic device configuredwith an energy harvester.

FIG. 11 is a block diagram illustrating an electronic device configuredwith an energy harvester.

FIG. 12 is a diagram illustrating a cross sectional view of a powerdistribution in a mobile electronic device configured with an energyharvester.

FIG. 13 is a diagram illustrating a cross sectional view of a powerdistribution in a mobile electronic device configured with an energyharvester.

FIG. 14 is a diagram illustrating a cross sectional view of a powerdistribution in a mobile electronic device configured with an energyharvester.

FIG. 15 is a diagram illustrating a cross sectional view of a powerdistribution in a mobile electronic device configured with an energyharvester.

FIG. 16 is a flow chart 1600 of a method for harvesting energy in anelectronic device.

FIG. 17 is a conceptual flow diagram illustrating the power flow betweendifferent modules/means/components in an exemplary apparatus.

FIG. 18 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of harvesting energy in an electronic device will now bepresented with reference to various apparatus and methods. Theseapparatus and methods will be described in the following detaileddescription and illustrated in the accompanying drawings by variousblocks, modules, components, circuits, steps, processes, algorithms,etc. (collectively referred to as “elements”). These elements may beimplemented using electronic hardware, computer software, or anycombination thereof. Whether such elements are implemented as hardwareor software depends upon the particular application and designconstraints imposed on the overall system.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented with a “processing system”that includes one or more processors. Examples of processors includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits, andother suitable hardware configured to perform the various functionalitydescribed throughout this disclosure. One or more processors in theprocessing system may execute software. Software shall be construedbroadly to mean instructions, instruction sets, code, code segments,program code, programs, subprograms, software modules, applications,software applications, software packages, routines, subroutines,objects, executables, threads of execution, procedures, functions, etc.,whether referred to as software, firmware, middleware, microcode,hardware description language, or otherwise.

Accordingly, in one or more exemplary embodiments, the functionsdescribed may be implemented in hardware, software, firmware, or anycombination thereof. If implemented in software, the functions may bestored on or encoded as one or more instructions or code on acomputer-readable medium. Computer-readable media includes computerstorage media. Storage media may be any available media that can beaccessed by a computer. By way of example, and not limitation, suchcomputer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code in the form of instructions or data structures and that canbe accessed by a computer. Disk and disc, as used herein, includescompact disc (CD), laser disc, optical disc, digital versatile disc(DVD), floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

An energy harvester is a device that can capture energy from an outsidesource. In one configuration, an energy harvester may include athermoelectric transducer, which can be used to harness thermal energyby converting the thermal energy to electrical energy. Such athermoelectric transducer may typically include a heat receiver, a heattransmitter, and a thermal channel coupled between the heat receiver andthe heat transmitter. The theoretical limit of the maximum possibleefficiency for thermoelectrical conversion is the Carnot limit, whichcan be determined using the following equation:Carnot limit=(T _(hot) −T _(cold))/T _(hot)  (equation 1)

where T_(hot) and T_(cold) are absolute temperatures in Kelvin (K). Forexample, if there is a thermal flow between a heat source at 100 degreesCelsius (° C.) (i.e., T_(hot)=373K) and a heat sink at 20° C. (i.e.,T_(cold)=293K), the Carnot limit will be 21.4%. The power gainassociated with the Carnot limit is known to be the reciprocal of theCarnot limit Therefore, in this example, the power gain will be 4.67.

FIG. 1 is a diagram illustrating an energy harvester configuration 100for converting thermal energy to electrical energy via a conductivethermal channel. As shown in FIG. 1 the energy harvester 101 includes ahot pad 102, a cold pad 106, and a conductive thermal channel 104. Theconductive thermal channel 104 is coupled between the hot pad 102 andthe cold pad 106. In one configuration, the conductive thermal channel104 may be a physical connection between the hot pad 102 and the coldpad 106. For example, the hot pad 102 and the cold pad 106 may eachinclude a conductive material, such as copper, and the conductivethermal channel 104 may be a wire bond, a wire on a printed circuitboard (PCB) or a printed wiring board (PWB), a thermal diode or aspecific material for optimum efficiency in converting thermal energy toelectrical energy. A thermal diode is a type of diode that isimplemented in a thermoelectric semiconductor, and designed either forenergy conversion or for refrigeration. It has been shown that a thermaldiode having a cold-side including Hg_(0.86)Cd_(0.14)Te[mercury-cadmium-telluride] and a hot-side including InSb [indiumantimonide] may achieve a maximum efficiency of 35%.

As shown in FIG. 1, the hot pad 102 is coupled to the hot region 103 andthe cold pad 106 is coupled to the cold region 107. For example, the hotregion 103 may be a bonding pad situated on a semiconductor die (alsoreferred to as a “semiconductor chip”) and the cold region 107 may be abonding pad situated on a different semiconductor die or a substrate.For example, the hot region 103 may be at 100° C. and the cold region107 may be at 20° C. As shown in FIG. 1, the temperature differencebetween the hot pad 102 and the cold pad 106 causes a flow of thermallyinduced electrons from the hot pad 102 to the cold pad 106 via theconductive thermal channel 104 and produces an electric potential (i.e.,a voltage amount “V”) across the hot pad 102 and the cold pad 106.

FIG. 2 is a diagram illustrating an exemplary electrical circuit 200showing the energy harvester 101 driving an electrical load 202. In FIG.2, the hot pad 102 and the cold pad 106 of energy harvester 101 arecoupled to the electrical load 202, such that the voltage producedacross the hot pad 102 and the cold pad 106 drives the electrical load202. For example, the electrical load 202 may be an integrated circuitor a battery.

FIG. 3 is a diagram illustrating a semiconductor die 300 configured withan energy harvester. As shown in FIG. 3, the energy harvester includesthe hot pad 302, the conductive thermal channel 304, and the cold pad306. The hot pad 302 is situated on a hot region of semiconductor die300 and the cold pad 306 is situated on a cold region of thesemiconductor die 300.

FIG. 4 is a diagram illustrating a semiconductor die 400 configured withan energy harvester. As shown in FIG. 4, the energy harvester 401includes the hot pad 402, the conductive thermal channel 404, and thecold pad 406. The hot pad 402 is situated on a hot region 403 ofsemiconductor die 400 and the cold pad 406 is situated on a cold region407 of the semiconductor die 400.

FIG. 5 is a diagram illustrating a top view of a multiple semiconductordie configuration 500 including an energy harvester. As shown in FIG. 5,multiple semiconductor die configuration 500 includes semiconductor die508 situated over semiconductor die 510. The energy harvester 501includes the hot pad 502, the conductive thermal channel 504, and thecold pad 506. The hot pad 502 is situated on a hot region 503 ofsemiconductor die 508 and the cold pad 506 is situated on a cold region507 of the semiconductor die 510.

FIG. 6 is a diagram illustrating a top view of a multiple semiconductordie configuration 600 including an energy harvester. As shown in FIG. 6,multiple semiconductor die configuration 600 includes semiconductor die608 situated above semiconductor die 610. As further shown in FIG. 6,the semiconductor die 610 is situated above the substrate 616, which maybe a substrate of an IC. The energy harvester 601 includes the hot pad602, the conductive thermal channel 604, and the cold pad 606. The hotpad 602 is situated on the hot region 603 of the semiconductor die 608and the cold pad 606 is situated on the cold region 607 of thesemiconductor die 610. In the configuration of FIG. 6, the conductivethermal channel 604 is situated on the surface of substrate 616, suchthat one end of the conductive thermal channel 604 is coupled to the hotpad 602 via the connection 612 and another end of the conductive thermalchannel 604 is coupled to the cold pad 606 via the connection 614.

FIG. 7 is a diagram illustrating an energy harvester configuration 700for converting thermal energy to electrical energy via a radiativethermal channel. As shown in FIG. 7, energy harvester 701 includes thehot pad 702, the cold pad 706, and the radiative thermal channel 704.The radiative thermal channel 704 is coupled between the hot pad 702 andthe cold pad 706. In the configuration of FIG. 7, the radiative thermalchannel 704 is an air gap between the hot pad 702 and the cold pad 706.For example, the hot pad 702 and the cold pad 706 may each be aconductive material, such as a copper.

As shown in FIG. 7, the hot pad 702 is coupled to the hot region 703 andthe cold pad 706 is coupled to the cold region 707. For example, the hotregion 703 may be a bonding pad situated on a semiconductor die and thecold region 707 may be a bonding pad situated on a differentsemiconductor die or a substrate. For example, the hot region 703 may beat 100° C. and the cold region 707 may be at 20° C. As shown in FIG. 7,the temperature difference between the hot pad 702 and the cold pad 706produces an electric potential (i.e., a voltage amount “V”) across thehot pad 702 and the cold pad 706. The electric potential may be used todrive an electrical load, such as an IC or a battery.

FIG. 8 is a diagram illustrating a top view of a multiple semiconductordie configuration 800 including an energy harvester. Multiplesemiconductor die configuration 800 includes a semiconductor die 802situated above a semiconductor die 804. As shown in FIG. 8, thesemiconductor die 802 has a hot region and the semiconductor die 804 hasa cold region. An energy harvester (not shown in FIG. 8) may be situatedbetween the semiconductor die 802 and the semiconductor die 804 asdescribed with reference to FIG. 9.

FIG. 9 is a diagram illustrating a cross sectional view of the multiplesemiconductor die configuration 800 shown in FIG. 8. As shown in FIG. 9,the energy harvester includes the hot pad 902, the cold pad 906, and theradiative thermal channel 904. In the configuration of FIG. 9, theradiative thermal channel 904 is an air gap between the semiconductordie 802 and semiconductor die 804. The hot pad 902 is coupled to a hotregion on semiconductor die 802 and the cold pad 906 is coupled to acold region on the semiconductor die 804.

In FIGS. 3-6, 8 and 9, electrical loads that may be driven by an energyharvester have been omitted for ease of illustration and to maintainclarity. Moreover, it should be understood that the semiconductor diesdiscussed in FIGS. 3-6, 8 and 9 may be situated in an IC. It should alsobe understood that more than two semiconductor dies may be included inan IC. For example, if an IC is a dynamic random access memory (DRAM)IC, then such IC may include six semiconductor dies in a multi-chippackage (MCP) and four semiconductor dies in a package on package (PoP).

FIG. 10 is a block diagram illustrating an electronic device 1000configured with an energy harvester. For example, the electronic device1000 may be an electronic component, such as an IC, situated in a mobileelectronic device, such as a mobile phone or a laptop. The electronicdevice 1000 includes power region (“PWR_REGION i”) 1002 having powerpins/nets (“VDD PIN i”) 1004 and ground pins/nets (“GND PIN i”) 1006.The electronic device 1000 further includes a hot region (“REGION i”)1010, which may be a hot surface of a semiconductor die in theelectronic device 1000. The electronic device 1000 further includesenergy harvester 1012 having a thermal channel 1016 coupled between apair of hot and cold pads. As shown in FIG. 10, one end of the thermalchannel 1016 is coupled to the hot pad (“HPAD i”) 1014 situated in thehot region 1010 and another end of the thermal channel 1016 is coupledto a cold pad (“CPAD i”) 1018 situated in a cold region of theelectronic device 1000, such as on the substrate in the electronicdevice 1000. Therefore, the hot pad 1014 may be used as a transmit portfor transmitting thermal energy and cold pad 1018 may be used as areceiver port for receiving electrical energy.

It should be understood that electronic device 1000 may be configured toinclude one or more pairs of hot and cold pads, each pair of hot andcold pads having a thermal channel coupled between the hot and coldpads. In the configuration of FIG. 10, the hot pad 1014 represents anith thermal pad in a high temperature region of the electronic device1000 and the cold pad 1018 represents an ith thermal pad in a relativelylow temperature region of the electronic device 1000, where thedifference in temperature between the high temperature region and thelow temperature region enables the energy harvester 1012 to convertthermal energy into electrical energy (also referred to as “harvestedelectrical energy”) via the thermal channel 1016. The thermal channel1016 may be a conductive thermal channel as previously discussed withrespect to FIG. 1 or a radiative thermal channel as discussed withrespect to FIG. 7.

The electronic device 1000 may include internal connections from pads tocorresponding external solder balls/pins, which may be configured forpower/ground or signals. Such internal connections may be either a flipchip type or a wire bond type. As shown in FIG. 10, the hot pad 1014 maybe coupled to power pins/nets 1004 and the cold pad 1018 may be coupledto ground pins/nets 1006. Therefore, the energy harvester 1012 maydeliver harvested electrical energy from the hot pad 1014 to the powerpins/nets 1004.

In FIG. 10, an optional direct current-to-direct current (DC/DC)converter 1008 is optionally coupled between the power pins/nets 1004and the ground pins/nets 1006. For example, if the temperature at thehot pad 1014 increases substantially above approximately 220° C., theDC/DC converter 1008 may not be needed due to the high conversionefficiency of the energy harvester 1012 at such high temperatures.However, since the temperature of electronic device packages aregenerally controlled so as not to exceed a predefined maximum casetemperature of 85° C., for example, at the top of the electronic devicepackage, the DC/DC converter 1008 may be used to boost the harvestedelectrical energy. In one configuration, the harvested electrical energymay be used by the electronic device 1000 as it is being generated bythe energy harvester 1012. In another configuration, the harvestedelectrical energy may be stored for later use or delivered to anotherelectronic device.

FIG. 11 is a block diagram illustrating an electronic device 1100configured with an energy harvester. For example, the electronic device1100 may be an electronic component, such as an IC, situated in a mobileelectronic device, such as a mobile phone or a laptop. The electronicdevice 1100 includes power region (“PWR_REGION 1”) 1102 having a powerpin/net (“VDD PIN 1”) 1104 and a ground pin/net (“GND PIN 1”) 1106. Theelectronic device 1100 further includes a hot region (“REGION 1”) 1110,which may be a hot surface of a semiconductor die of the electronicdevice 1100. The electronic device 1100 further includes energyharvester 1112 having a thermal channel 1116 coupled between a pair ofhot and cold pads. As shown in FIG. 11, one end of the thermal channel1116 is coupled to a hot pad (“HPAD 1”) 1114 situated in the hot region1110 and another end of the thermal channel 1116 is coupled to a coldpad (“CPAD 1”) 1118 situated in a cold region of the electronic device1100, such as on the substrate of the electronic device 1100. Therefore,the hot pad 1114 may be used as a transmit port for transmitting thermalenergy and cold pad 1018 may be used as a receiver port for receivingconverted electrical energy.

In the configuration of FIG. 11, since the hot pad 1114 is situated in ahigh temperature region (e.g., “Region 1” 1110) of the electronic device1100 and the cold pad 1118 is situated in a relatively low temperatureregion, the difference in temperature between the high temperatureregion and the low temperature region enables the energy harvester 1112to convert thermal energy into electrical energy via the thermal channel1116. The thermal channel 1116 may be a conductive thermal channel aspreviously discussed with respect to FIG. 1 or a radiative thermalchannel as discussed with respect to FIG. 7.

As shown in FIG. 11, the hot pad 1114 may be coupled to power pin/net1104 and the cold pad 1118 may be coupled to ground pin/net 1106.Therefore, the energy harvester 1112 may deliver harvested electricalenergy from the hot pad 1114 to the power pin/net 1104. In theconfiguration of FIG. 11, the optional DC/DC converter 1108 is coupledbetween the power pin/net 1104 and the ground pin/net 1106 to boost theharvested electrical energy. In other configurations, the DC/DCconverter 1108 may be omitted. The harvested electrical energy may beused by the electronic device 1100 and/or the mobile electronic deviceas it is being generated by the energy harvester 1112 or may be storedfor later use.

The configuration of FIG. 11 includes four hot pads (e.g., hot pads1114, 1120, 1122, and 1124). Accordingly, multiple energy harvesters maybe used for either boosting a single power supply net or boostingmultiple independent power nets. It can be appreciated that one ormultiple energy harvesters may be used for an optimum design.

FIG. 12 is a diagram illustrating a cross sectional view of a powerdistribution in a mobile electronic device 1200 configured with anenergy harvester. The mobile electronic device 1200 includes IC 1202,capacitor 1225, DC/DC converter 1226, battery charger module 1228,battery 1230, power management IC 1232, and external load 1234. Forexample, the external load 1234 may include light emitting diodes (LEDs)and discrete radio frequency (RF) components. In one configuration, theIC 1202 may be a processor. As shown in FIG. 12, IC 1202 includes energyharvester 1203, which includes a semiconductor material 1208 coupled toa hot region of semiconductor die 1206, a semiconductor material 1212coupled to a cold region of semiconductor die 1214, and a conductivethermal channel coupled between the semiconductor materials 1208 and1212. The energy harvester 1203 further includes the hot pad 1204situated at the exterior of semiconductor die 1206 and coupled to thesemiconductor material 1208 via conductive path 1218, and furtherincludes the cold pad 1216 situated at the exterior of semiconductor die1214 and coupled to the semiconductor material 1212 via conductive path1220. For example, the semiconductor material 1208 may be an n-typesemiconductor material and the semiconductor material 1212 may be ap-type semiconductor material. As shown in FIG. 12, the semiconductormaterial 1208 is isolated from the cold region of semiconductor die 1214and the semiconductor material 1212 is isolated from the hot region ofsemiconductor die 1206.

The conductive thermal channel 1210 may be a conductive material, suchas a wire. As shown in FIG. 12, the hot pad 1204 is coupled to the powerplane 1222 and the cold pad 1216 is coupled to the ground plane 1224. Inthe configuration of FIG. 12, the battery 1230 is the primary powersource for the mobile electronic device 1200, which provides power tothe power management IC 1232. The power management IC 1232 providespower to the DC/DC converter 1226, which then provides power to the IC1202. The capacitor 1225 is configured to suppress noise on the powerplane 1222.

In the configuration of FIG. 12, the IC 1202 receives power via thepower plane 1222. As the mobile electronic device 1200 operates the IC1202, the energy harvester 1203 may be configured to convert thermalenergy generated by the semiconductor die 1206 into electrical energyvia the conductive thermal channel 1210. Accordingly, the energyharvester 1203 may deliver the harvested electrical energy to the IC1202 or to the DC/DC converter 1226 for supplying power to the externalload 1234.

FIG. 13 is a diagram illustrating a cross sectional view of a powerdistribution in a mobile electronic device 1300 configured with anenergy harvester. The mobile electronic device 1300 includes IC 1302,capacitor 1325, DC/DC converter 1326, battery charger module 1328,battery 1330, power management IC 1332, and external load 1334. In oneconfiguration, the IC 1302 may be a processor. As shown in FIG. 13, IC1302 includes energy harvester 1303, which includes a semiconductormaterial 1308 coupled to a hot region of semiconductor die 1306, asemiconductor material 1312 coupled to a cold region of semiconductordie 1314, and a conductive thermal channel 1310 coupled between thesemiconductor materials 1308 and 1312. The energy harvester 1303 furtherincludes the hot pad 1304 coupled to the semiconductor material 1308,and further includes the cold pad 1316 coupled to the semiconductormaterial 1312. For example, the semiconductor material 1308 may be ann-type semiconductor material and the semiconductor material 1312 may bea p-type semiconductor material. As shown in FIG. 13, the semiconductormaterial 1308 is isolated from the cold region of semiconductor die 1314and the semiconductor material 1312 is isolated from the hot region ofsemiconductor die 1306.

The conductive thermal channel 1310 may be a conductive material, suchas a wire. As shown in FIG. 13, the hot pad 1304 is coupled to the powerplane 1322 and the cold pad 1316 is coupled to the ground plane 1324. Inthe configuration of FIG. 13, the battery 1330 is the primary powersource for the mobile electronic device 1300, which provides power tothe power management IC 1332. The power management IC 1332 providespower to the DC/DC converter 1326, which then provides power to the IC1302.

In the configuration of FIG. 13, the IC 1302 receives power via thepower plane 1322. As the mobile electronic device 1300 operates the IC1302, the energy harvester 1303 may be configured to convert thermalenergy generated by the semiconductor die 1306 into electrical energyvia the conductive thermal channel 1310. Accordingly, the energyharvester 1303 may deliver the harvested electrical energy to the IC1302 or to the DC/DC converter 1326 for supplying power to the externalload 1334.

FIG. 14 is a diagram illustrating a cross sectional view of a powerdistribution in a mobile electronic device 1400 configured with anenergy harvester. The mobile electronic device 1400 includes IC 1402,capacitor 1425, DC/DC converter 1426, battery charger module 1428,battery 1430, power management IC 1432, and external load 1434. In oneconfiguration, the IC 1402 may be a processor. As shown in FIG. 14, IC1402 includes energy harvester 1403, which includes the hot pad 1404coupled to the hot region of the semiconductor die 1410, and furtherincludes the cold pad 1416 coupled to the cold region of thesemiconductor die 1414. The energy harvester 1403 further includes theradiative thermal channel 1412 coupled between the hot region of thesemiconductor die 1410 and the cold region of the semiconductor die1414. In the configuration of FIG. 14, the radiative thermal channel1412 is an air gap.

As shown in FIG. 14, the hot pad 1404 is coupled to the power plane 1422and the cold pad 1416 is coupled to the ground plane 1424. In theconfiguration of FIG. 14, the battery 1430 is the primary power sourcefor the mobile electronic device 1400, which provides power to the powermanagement IC 1432. The power management IC 1432 provides power to theDC/DC converter 1426, which then provides power to the IC 1402.

In the configuration of FIG. 14, the IC 1402 receives power via thepower plane 1422. As the mobile electronic device 1400 operates the IC1402, the energy harvester 1403 may be configured to convert thermalenergy generated by the semiconductor die 1410 into electrical energyvia the radiative thermal channel 1412. Accordingly, the energyharvester 1403 may deliver the harvested electrical energy to the IC1402 or to the DC/DC converter 1426 for supplying power to the externalload 1434.

FIG. 15 is a diagram illustrating a cross sectional view of a powerdistribution in a mobile electronic device 1500 configured with anenergy harvester. The mobile electronic device 1500 includes IC 1502,capacitor 1525, DC/DC converter 1526, battery charger module 1528,battery 1530, power management IC 1532, and external load 1534. In oneconfiguration, the IC 1502 may be a processor. As shown in FIG. 15, IC1502 includes energy harvester 1503, which includes the hot pad 1504coupled to the hot region of the semiconductor die 1506, and furtherincludes the cold pad 1514 coupled to the cold region of thesemiconductor die 1516. The energy harvester 1503 further includes theradiative thermal channel 1512 coupled between the hot region of thesemiconductor die 1506 and the cold region of the semiconductor die1516. In the configuration of FIG. 15, the radiative thermal channel1512 is an air gap.

As shown in FIG. 15, the hot pad 1504 is coupled to the power plane 1522and the cold pad 1514 is coupled to the ground plane 1524. In theconfiguration of FIG. 15, the battery 1530 is the primary power sourcefor the mobile electronic device 1500, which provides power to the powermanagement IC 1532. The power management IC 1532 provides power to theDC/DC converter 1526, which then provides power to the IC 1502.

In the configuration of FIG. 15, the IC 1502 receives power via thepower plane 1522. As the mobile electronic device 1500 operates the IC1502, the energy harvester 1503 may be configured to convert thermalenergy generated by the semiconductor die 1506 into electrical energyvia the radiative thermal channel 1512. Accordingly, the energyharvester 1503 may deliver the harvested electrical energy to the IC1502 or to the DC/DC converter 1526 for supplying power to the externalload 1534.

FIG. 16 is a flow chart 1600 of a method for harvesting energy in anelectronic device. At step 1602, the electronic device may operate anelectronic component. In one configuration, the electronic component maybe an IC. For example, the mobile device may include a power source,such as a battery, for powering the IC.

At step 1604, the mobile device may receive power from at least oneenergy harvester coupled between at least one pair of hot and coldregions of the electronic component and configured to convert thermalenergy to electrical energy, the at least one energy harvester includinga radiative thermal channel or a conductive thermal channel. A first endof the conductive thermal channel is coupled to a first semiconductormaterial and a second end of the conductive thermal channel is coupledto a second semiconductor material, the first semiconductor materialbeing coupled to the hot region and isolated from the cold region andthe second semiconductor material being coupled to the cold region andisolated from the hot region. For example, the first semiconductormaterial may be an n-type semiconductor material and the secondsemiconductor material may be a p-type semiconductor material. Thedifference in temperature between the hot and cold regions of theelectronic component enables the energy harvester to convert thermalenergy into electrical energy. The hot region may be a bonding padsituated on a first die of the electronic component and the cold regionmay be a different bonding pad situated on a substrate or a second dieof the electronic component. In an aspect, the hot region may be a firstpad coupled to a power pin of the electronic component and the coldregion may be a second pad coupled to a ground pin of the electroniccomponent. In one configuration, the conductive thermal channel mayinclude a wire bond. In another configuration, the radiative thermalchannel may be an air gap.

At step 1606, the mobile device may power at least the electroniccomponent using the electrical energy. For example, the mobile devicemay use the harvested electrical energy to power the electroniccomponent as it is being generated by the energy harvester.Alternatively, the mobile device may store the harvested electricalenergy for later use or deliver the harvested electrical energy toanother electronic device.

FIG. 17 is a conceptual flow diagram 1700 illustrating the power flowbetween different modules/means/components in an exemplary apparatus1702. The apparatus may be a mobile device. The apparatus 1702 includesa power module 1704, an electronic component operating module 1706, anelectronic component module 1708, and an optional DC/DC converter module1710.

The power module 1704 provides power to the electronic componentoperating module 1706 and the electronic component module 1708. In oneconfiguration, the power module 1704 may be a battery configured tosupply power to the apparatus 1702. The electronic component operatingmodule 1706 operates (e.g., activates and/or controls) the electroniccomponent module 1708. In one configuration, the electronic componentoperating module 1706 may be a processor and the electronic componentmodule 1708 may be a memory IC package. In another configuration, theelectronic component operating module 1706 and the electronic componentmodule 1708 may each be a processor.

The power module 1704 receives power from at least one energy harvestercoupled between at least one pair of hot and cold regions of theelectronic component module 1708 and configured to convert thermalenergy to electrical energy. The at least one energy harvester mayinclude a radiative thermal channel or a conductive thermal channel. Afirst end of the conductive thermal channel is coupled to a firstsemiconductor material and a second end of the conductive thermalchannel is coupled to a second semiconductor material, the firstsemiconductor material being coupled to the hot region and isolated fromthe cold region and the second semiconductor material being coupled tothe cold region and isolated from the hot region. For example, the firstsemiconductor material may be an n-type semiconductor material and thesecond semiconductor material may be a p-type semiconductor material.The hot region may be a bonding pad situated on a first die of theelectronic component module 1708 and the cold region may be a differentbonding pad situated on a substrate or a second die of the electroniccomponent module 1708. In an aspect, the hot region may be a first padcoupled to a power pin of the electronic component module 1708 and thecold region may be a second pad coupled to a ground pin of theelectronic component module 1708. In one configuration, the conductivethermal channel may include a wire bond. In another configuration, theradiative thermal channel may be an air gap. The power module 1704 mayalso receive power from an outside source, such as an external powersupply.

In one configuration, the electronic component module 1708 providesharvested electrical energy to the optional DC/DC converter module 1710,which is configured to boost the harvested electrical energy and toprovide the boosted electrical energy to the power module 1704.

The apparatus may include additional modules that perform each of thesteps in the aforementioned flow chart FIG. 16. As such, each step inthe aforementioned flow chart FIG. 16 may be performed by a module andthe apparatus may include one or more of those modules. The modules maybe one or more hardware components specifically configured to carry outthe stated processes/algorithm, implemented by a processor configured toperform the stated processes/algorithm, stored within acomputer-readable medium for implementation by a processor, or somecombination thereof.

FIG. 18 is a diagram illustrating an example of a hardwareimplementation for an apparatus 1702′ employing a processing system1814. The processing system 1814 may be implemented with a busarchitecture, represented generally by the bus 1824. The bus 1824 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1814 and the overalldesign constraints. The bus 1824 links together various circuitsincluding one or more processors and/or hardware modules, represented bythe processor 1804, the modules 1704, 1706, 1708, and 1710, and thecomputer-readable medium 1806. The bus 1824 may also link various othercircuits such as timing sources, peripherals, voltage regulators, andpower management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 1814 may be coupled to a transceiver 1810. Thetransceiver 1810 is coupled to one or more antennas 1820. Thetransceiver 1810 provides a means for communicating with various otherapparatus over a transmission medium. The processing system 1814includes a processor 1804 coupled to a computer-readable medium 1806.The processor 1804 is responsible for general processing, including theexecution of software stored on the computer-readable medium 1806. Thesoftware, when executed by the processor 1804, causes the processingsystem 1814 to perform the various functions described supra for anyparticular apparatus. The computer-readable medium 1806 may also be usedfor storing data that is manipulated by the processor 1804 whenexecuting software. The processing system further includes at least oneof the modules 1704, 1706, 1708, and 1710. The modules may be softwaremodules running in the processor 1804, resident/stored in the computerreadable medium 1806, one or more hardware modules coupled to theprocessor 1804, or some combination thereof.

In one configuration, the apparatus 1702/1702′ includes means foroperating an electronic component, means for receiving power from atleast one energy harvester coupled between at least one pair of hot andcold regions of the electronic component and configured to convertthermal energy to electrical energy, the at least one energy harvestercomprising a radiative thermal channel or a conductive thermal channel,and means for powering at least the electronic component using theelectrical energy. The aforementioned means may be one or more of theaforementioned modules of the apparatus 1702 and/or the processingsystem 1814 of the apparatus 1702′ configured to perform the functionsrecited by the aforementioned means.

Therefore, by converting thermal energy output by ICs into electricalenergy, the battery life of mobile electronic devices using highperformance/speed ICs may be advantageously extended. For example,standby time of the mobile electronic devices may be extended byharvesting energy while being used for running applications that consumesubstantial amounts of power (e.g., multimedia applications).Accordingly, users of mobile electronic devices will experience longerbattery life and, therefore, may require less frequent recharging of thebatteries powering the mobile electronic devices. For example, a usermay need to recharge a battery less often, such as only once per day orweek.

In addition, conventional low power design efforts can be redirected tomore demanding areas, such as performance enhancement of the ICs.Moreover, the energy harvester configurations disclosed herein may beimplemented by maintaining current hardware design methodology,including PCB routing and stacking of multiple dies/chips in an IC.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an illustration of exemplary approaches. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged. Further, somesteps may be combined or omitted. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed as a means plus functionunless the element is expressly recited using the phrase “means for.”

What is claimed is:
 1. An electronic component comprising: at least oneenergy harvester coupled between at least one pair of hot and coldregions of the electronic component and configured to convert thermalenergy to electrical energy in order to provide power to at least theelectronic component, the at least one energy harvester comprising aconductive thermal channel, wherein a difference in voltage is presentbetween a first end and a second end of the conductive thermal channelwhen the at least one energy harvester is in operation, the first endand the second end of the conductive thermal channel defining an axis ofthe conductive thermal channel, wherein the first end of the conductivethermal channel is connected solely to an n-type semiconductor materialof the electronic component and the second end of the conductive thermalchannel is connected solely to a p-type semiconductor material of theelectronic component, the n-type semiconductor material being coupled tothe hot region and spaced apart from the cold region by the conductivethermal channel and the p-type semiconductor material with respect tothe axis of the conductive thermal channel, and the p-type semiconductormaterial being coupled to the cold region and spaced apart from the hotregion by the conductive thermal channel and the n-type semiconductormaterial with respect to the axis of the conductive thermal channel,wherein the at least one energy harvester further comprises a first pad,coupled to the n-type semiconductor and a power pin, the first padspaced apart from the cold region at least partially by the conductivethermal channel, and wherein the at least one energy harvester furthercomprises a second pad, coupled to the p-type semiconductor and a groundpin, the second pad spaced apart from the hot region at least partiallyby the conductive thermal channel.
 2. The electronic component of claim1, wherein: the conductive thermal channel comprises a wire bond; andthe at least one energy harvester further comprises a radiative thermalchannel, the radiative thermal channel comprising an air gap.
 3. Theelectronic component of claim 1, wherein: the hot region is a firstbonding pad situated on a first die; and the cold region is a secondbonding pad situated on a substrate or a second die.
 4. The electroniccomponent of claim 1, wherein the at least one energy harvester isfurther coupled to a direct current-to-direct current (DC/DC) converter.5. The electronic component of claim 1, wherein the electronic componentis an integrated circuit (IC).
 6. The electrical component of claim 1,wherein the conductive thermal channel comprises a thermal diode.
 7. Theelectrical component of claim 1, wherein the first pad is directlyconnected to the n-type semiconductor and the second pad is directlyconnected to the p-type semiconductor.
 8. The electrical component ofclaim 1, wherein the first pad is connected to the n-type semiconductorvia a first conductive path, the first pad spaced apart from the n-typesemiconductor by the hot region, and wherein the second pad is connectedto the p-type semiconductor via a second conductive path, the second padspaced apart from the p-type semiconductor by the cold region.
 9. Amobile device comprising: an electronic component; and at least oneenergy harvester coupled between at least one pair of hot and coldregions of the electronic component and configured to convert thermalenergy to electrical energy in order to provide power to at least theelectronic component, the at least one energy harvester comprising aconductive thermal channel, wherein a difference in voltage is presentbetween a first end and a second end of the conductive thermal channelwhen the at least one energy harvester is in operation, the first endand the second end of the conductive thermal channel defining an axis ofthe conductive thermal channel, wherein the first end of the conductivethermal channel is connected solely to an n-type semiconductor materialof the electronic component and the second end of the conductive thermalchannel is connected solely to a p-type semiconductor material of theelectronic component, the n-type semiconductor material being coupled tothe hot region and spaced apart from the cold region by the conductivethermal channel and the p-type semiconductor material with respect tothe axis of the conductive thermal channel, and the p-type semiconductormaterial being coupled to the cold region and spaced apart from the hotregion by the conductive thermal channel and the n-type semiconductormaterial with respect to the axis of the conductive thermal channel,wherein the at least one energy harvester further comprises a first pad,coupled to the n-type semiconductor and a power pin, the first padspaced apart from the cold region at least partially by the conductivethermal channel, and wherein the at least one energy harvester furthercomprises a second pad, coupled to the p-type semiconductor and a groundpin, the second pad spaced apart from the hot region at least partiallyby the conductive thermal channel.
 10. The mobile device of claim 9,wherein: the conductive thermal channel comprises a wire on a printedcircuit board (PCB) or a printed wiring board (PWB); and the at leastone energy harvester further comprises a radiative thermal channel, theradiative thermal channel comprising an air gap.
 11. The mobile deviceof claim 9, wherein: the hot region is coupled to a first pad situatedon a hot component on a printed circuit board (PCB); and the cold regionis coupled to a second pad situated on a substrate or a cold componenton the PCB.
 12. The mobile device of claim 9, wherein the at least oneenergy harvester is further coupled to a direct current-to-directcurrent (DC/DC) converter.
 13. The mobile device of claim 9, wherein theelectronic component is an integrated circuit (IC).
 14. The mobiledevice of claim 9, wherein the conductive thermal channel comprises athermal diode.
 15. The mobile device of claim 9, wherein the first padis directly connected to the n-type semiconductor and the second pad isdirectly connected to the p-type semiconductor.
 16. The mobile device ofclaim 9, wherein the first pad is connected to the n-type semiconductorvia a first conductive path, the first pad spaced apart from the n-typesemiconductor by the hot region, and wherein the second pad is connectedto the p-type semiconductor via a second conductive path, the second padspaced apart from the p-type semiconductor by the cold region.